How to denoise animations using Blender's Temporal Denoiser?
How to use the Temporal Denoiser

Step 01: Pack Denoising Data

Enable denoising data in View Layer &gt; Passes &gt; Denoising Data
Set file format to OpenEXR Multilayer (so Blender packs the denoising data)
Render your animation



Note:
Blender 2.8 needs to be used in the pipeline to pack the denoising data. Simply open your .blend with Blender 2.8, set up the denoising data and save. Then you can reopen the file and render with any version.






Step 02: Denoising
import bpy
import os 
import glob

inputdir=&quot;D:/Animation/&quot;
outputdir=&quot;D:/Animation/Denoised_&quot;
os.chdir(inputdir)
myfiles=(glob.glob(&quot;*.exr&quot;))
for file in myfiles:
   print(inputdir + file + &quot; to &quot; + outputdir + file)
   bpy.ops.cycles.denoise_animation(input_filepath=(inputdir + file), output_filepath=(outputdir + file))
 


Copy the above script into Blender's Text Editor (and backup your animation files :)
Change the location to where your rendered files are. The default location is D:/Animation/
Run the script by pressing the Play button ►






Notes: The used code is from this Reddit thread. All credits to toadfury.